EXAMINATION
QUESTIONS

HKAL '89 

I-1 
A micrometer screw gauge is used to measure the diameter of a piece of wire. The following readings were obtained:
	mean zero reading		-0.05  0.02 mm, and
	mean apparent diameter	+1.05  0.02 mm.
The diameter of the wire should be written as
A.	1.00  0.02 mm	B.  1.00  0.04 mm
C.  	1.10  0.00 mm	D.  1.10  0.02 mm
E.	1.10  0.04 mm

HKAL '90 

I-1 
The formula  is used to calculate the acceleration due to gravity g.
If the maximum percentage error of l = 2% and the maximum percentage error of T = 5%, then the maximum percentage error for g will be
A.  3%     B.  8%     C.  12%      D.  23%     E.  27%

HKAL '92 

I-50 
To determine the area of cross-section of a metal wire, a student measures its diameter and obtains a value of 0.20 mm, subject to an error of  0.02 mm. Which of the following is the most appropriate way of expressing the result?
A.  0.03  0.01 mm2     	B.  0.031  0.003 mm2 
C.  0.031  0.006 mm2	D.  0.0314  0.0031 mm2
E.  0.0314  0.0063 mm2 

HKAL '93 

I-50 
A parallel-plate capacitor is formed by two square metal plates. To determine the capacitance C, a student measures the length of side l and separation d of the plates. (Given: )
If the maximum percentage error of l = 5%
   the maximum percentage error of d = 3%,
then the maximum percentage error for C will be 
A.  7%     B.  8%     C.  13%     D.  22%     E.  28%

HKAL '95

II-45 
In an experiment to measure the density of steel, a steel sphere was used. The following measurements were obtained:
	Mass of the sphere = 530 mg  1 mg
	Diameter of the sphere = 0.51 cm  0.01 cm
Estimate the percentage error in the calculated value of the density of steel.
A.  1%     B.  2%     C.  4%     D.  6%     E.  8%

HKAL '96 

II-45 
The period of oscillation, T, of a simple pendulum is related to its length, l, by the formula . To find experimentally the acceleration of free fall by using a simple pendulum, a student takes the following measurements:
	time for 15 oscillations : 14.4  0.2 s
	length of the pendulum : 0.229  0.001 m
Which of the following is the most appropriate way of expressing the result?
A.  9.8  0.2 m s-2         B.  9.8  0.3 m s-2 
C.  9.81  0.32 m s-2     D.  9.810  0.179 m s-2 
E.  9.810  0.315 m s-2 

HKAL '97 

II-45 
In an experiment to determine the period of oscillation, T, of a simple pendulum, the time, t, for a number of complete oscillations is taken. It is found that the time for 30 complete oscillations is 28.7  0.3 s. Which of the following statements is/are correct?
1) 	The reading error in t can be reduced by counting 50 oscillations.
2) 	The percentage error in T is the same as that in t.
3) 	The period T determined should be quoted as 0.96  0.01 s.
A. 	(1) only   B. (3) only   C. (1) & (2) only
D.  (2) & (3) only   E. (1), (2) & (3)